


Devil's Workshop

by TrasBen



Series: Skeleton Shipping [10]
Category: Undertale (Video Game)
Genre: ? - Freeform, Afterfell Sans (Undertale), Anxious Sans (Undertale), He kinda is, Hurt/Comfort, M/M, Mercy (Undertale) - Freeform, Post-Undertale Pacifist Route, Professor Sans (Undertale), Sans thinks red is a devil, Sans/Afterfell Sans (Undertale), Undertale Sans (Undertale), but not really, jazz hands, kustard - Freeform
Language: English
Status: Completed
Published: 2020-08-12
Updated: 2020-08-12
Packaged: 2021-03-06 00:42:28
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,889
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25854553
Author URL: https://archiveofourown.org/users/TrasBen/pseuds/TrasBen
Summary: They say idle hands are the devil's workshop, and there isn't a monster around more idle than Sans....Three years and he's done with his doppelganger's bullshit.
Relationships: Sans/Sans (Undertale)
Series: Skeleton Shipping [10]
Series URL: https://archiveofourown.org/series/1403878
Comments: 14
Kudos: 70





	Devil's Workshop

Sans had always thought that the little devil on his shoulder would be smaller. Maybe they would have a little pointy tail and curled horns. Perhaps they’d even have a voice only _slightly_ reminiscent of Skeletor, with an evil little laugh to go with it. And _maybe_ a little pitchfork, too.

But that was probably a little too cliche. Sans really should have expected that he’d be saddled with the kind of devil that’s just a strange, elusive asshole who likes to talk shit and untie people’s shoelaces.

Or maybe Sans really _is_ crazy and can’t tie a damn knot as well as he thinks he can. 

Except he could’ve _sworn_ that he’d done a double knot on his laces this morning, _specifically_ so this wouldn’t happen - but it doesn’t really matter what _Sans_ thinks, because when he stands from his desk and tries to take a step forward, he falls flat on his face for the hundredth time with a clatter and a groan.

The snickering from a few feet away tells him that the little devil’s struck again, which is only confirmed when he pulls himself up and sees that his shoelaces are sitting like limp spaghetti noodles on the floor.

Good thing class ended half an hour ago and Sans is in his office, or else he would have to deal with a whole lot more laughter and quite a few patronizing looks right now. As it turns out, having an annoying devil following in your shadow makes teaching lectures extremely difficult.

Especially if you’re a physics professor and the voice to your right keeps calling out wrong answers when you’re in the middle of explaining a formula.

The first couple of times it happened, Sans nearly mistook the voice for an overeager student. The very first time, he’d turned around, suddenly and irritated, only to find a sea of confused faces staring back, all wondering why he’d stopped in the middle of lecture to look back on his silent class.

A few seconds later, a girl in the front row pointed out that he’d written a three instead of a seven and Sans erased it with a burning skull, trying to ignore the smug grin of the devil sitting on his desk.

The devil, who has the smile of a shark and a skull suspiciously identical to Sans’ own. Like he’s some sort of evil twin who prefers to dress in dark clothes and regularly gets into fights, covered in scars and chips and with one glittering fang that _must_ be gold. 

Despite the devil looking nearly identical to Sans, he can say with confidence that he’s almost _nothing_ like the monster who shares his face. The monster who, despite everything, no one else can see. No one else can hear.

Whose preferred pastime is to antagonize Sans day in and day out with snide comments, intrusive thoughts, and terribly hilarious and mean-spirited commentary on nearly everyone Sans comes into contact with.

Not to mention that every time Sans falls asleep or gets distracted, his shoes miraculously untie themselves. One some occasions, he’s able to catch it before he falls on his face, but it’s just as often that he trips over his own feet and has to endure strange looks from strangers or a lecture from Papyrus on personal maintenance.

All the while his devil grins from the sidelines. 

_(And when did Sans decide the devil was_ his _? Probably when he realized it was intent on personally making Sans’ life_ hell _ishly complicated.)_

Sans has to make sure he doesn’t look over too often at the devil. Part of him still believes it’s all in his head, a hallucination brought on by stress or trauma or something else that Sans should’ve addressed years ago with a therapist. That part also believes that if Sans ignores the devil that it’ll go away on its own.

Well, three years later and the fucker’s still around, annoying laugh and all.

Wherever Sans goes, the devil is sure to follow, like in that human nursery rhyme about little girls and lambs. 

Except Sans’ devil reminds him more of a wolf than a sheep. Stalking Sans, just one step behind him when he walks. Sans can almost swear that he feels breath on the back of his cervical vertebrae when he pauses.

When Sans sits or lectures, the devil lazes around and tries to find anything to pick at until Sans is nearly driven mad.

But still, Sans hasn’t acknowledged what’s most likely the figment of his imagination once, nor does he plan to, until his subconscious gets the message. Sans is a master of pushing things down. The world champion, in fact. And he’s not about to give up his title over one annoying devil.

So Sans picks himself up from the ground with nothing more than a sigh, and doesn’t bother to tie his laces back up. He grabs his briefcase - an old, beat up thing with peeling leather and covered in hot dog stickers - and readies himself for a ‘shortcut’ home. 

Better than public transportation. Sans knows most of his paranoias are largely unfounded, but the memory of the last time he’d taken the subway is fresh in his mind.

It had only taken a second for the lights to flicker, for the car he’d been in to be engulfed in darkness. For Sans to feel the soft brush of phalanges against his cervical vertebrae, the barest imitation of a hold that could snap Sans’ skull clean off his body.

It had only taken a second for Sans to swear he’d never sleep with the lights off again.

The void is dark, too, but it’s the one place the devil doesn’t follow. The gaze Sans feels at all hours of the day and night fall away for that fraction of a moment, until Sans opens his sockets again and he’s in his room, and the devil is once again watching him from the corner with smouldering crimson eye lights.

With a heavy sigh, Sans sets his briefcase down on the ground and flops onto his bed. He can see the devil raise a brow bone from the corner of his socket, but he pretends not to. Pretends he thinks he’s alone.

“Sansy had a long day, huh?” The devil goads. Sharp toothed and sadistic, the devil draws in closer ‘til he’s only a foot away, standing above Sans. “Good thing you won’t be busy grading essays today.”

Sans’ face twitches as he recalls the essays his classes had handed in today. He swore to Papyrus that he’d get started grading them as soon as possible this time, to avoid the fiasco that was last semester, but….

“fuck.” Sans grits out.

He left them in his office.

“Oh ho ho, guess you remembered. Too bad we both know you’re gonna leave them there.”

Sans lets his sockets slip shut. He could go back and get the papers, but the devil’s infuriatingly correct. It’s too much work, especially after the _hell_ of a day he’s just had, what with the conference he’d had with a student after class. He’d managed to catch a nap after, but still…

He kicks off his infernal laced shoes and settles further back into his bed.

The devil snickers. “Knew it. Lazy bastard.”

A second later, Sans hears the creak of his old desk chair and knows that the devil’s sat down. Probably to settle in for his own long night of watching Sans twist and turn with that same smile.

Only the sound of Sans’ spinning ceiling fan pervades the silence of the room. For once, the devil is silent. Probably because he knows Sans is cursing himself for being so forgetful enough for the both of them.

And he’d be right. Mostly.

The other part of Sans is thinking about how intimate this is.

Him, laying on his bed. The devil, watching him from the desk chair. It’s sad, but Sans is almost more familiar with this than any other type of social interaction. A little part of him knows the devil and knows the devil knows _him,_ so even if Sans doesn’t talk or look at him, they both still _know._

Sans turns away from the devil to lay on his side.

He wonders if the devil is bored of watching a pathetic little skeleton tear his life apart piece by piece. Isolating himself in his room, eating only junk food and whatever Paps leaves outside his door.

Sans can’t even have a conversation with a human student in his own damn office without seeing those red eyes and flinching.

Probably not, considering the devil had been with him the whole way. Whispering confirmations to Sans’ dark thoughts, reminding him that humans can’t be trusted. Maybe the devil’s proud of himself, of his work.

Cruel words that make Sans more cynical. Jabs about others that Sans almost agrees with.

Three years of torture, of fighting himself. It’s a miracle Sans hasn’t given in yet. 

Why not?

Just on the principle?

It only takes a second for Sans to throw three years of careful work to the wind. He flips over onto his other side so he can stare directly at the devil sitting in his chair. The other’s feet are up on the desk, laces comically untied.

He’s picking at his sharp teeth, not even looking at Sans. 

It’s the first time Sans has gotten a really _good_ look at his devil, and it’s both under and overwhelming all at the same time. Underwhelming because the devil looks like such a regular monster that it’s easy to believe he _is._

Overwhelming because the puzzle pieces of the quick flashes Sans had gotten over the years are suddenly put together at all at once. He’d known that the devil shared his face, but to see it as clearly as his reflection in the mirror takes his breath away.

The devil remains ignorant of Sans’ stare for a few more moments, allowing him to observe the other for a bit longer. But it isn’t long until those crimson eye lights land on Sans once again and they constrict.

The devil jumps a little at Sans’ concentrated stare. It almost makes Sans huff out a little breath of amusement from his nasal cavity, but he doesn’t. He pretends the devil hadn’t moved at all and continues to stare.

Cautiously, the devil tilts his skull and looks Sans right in the eye lights. He has to suppress the shivers that roll down his spine. The devil waves his hand a little. There’s a bead of red sweat that grows on the other’s skull and Sans watches it as it trails down his face.

He’s nervous under Sans’ stare.

_heh. how does it feel? getting a taste of your own medicine…_

“You sleepin’ with your eyes open or something?” The devil asks eventually. “Guess I shouldn’t be surprised you got _dead_ eyes…” He adds, “since you ain’t got nothing in that empty skull of yours”

It’s not the first time Sans’ devil has made puns. It’s actually one of the few things they have in common. But his doppelganger’s jokes are usually much darker, a disguised jab at someone Sans had spoken to.

The words are out before Sans can stop them.

“takes one to know one.”

The devil does a double take and it’s almost hilarious. “The fuck did you just say?”

Sans swallows even though he doesn’t have to. It’s more of a nervous habit than anything. A habit his devil must have caught onto in the past three years. “i said,” Sans repeats, “takes one to know one. you called me a lazy bastard.”

Sans’ devil laughs. He actually laughs. And it’s not one of those snarky half-chuckles he does when Sans falls flat on his face or when something else unfortunate happens. It’s a disbelieving, _desperate_ sound.

“... I fuckin’ _knew_ you could see me.” He says almost reverently. “I knew it, I knew it.” The devil’s grin widens shakily, his sharp phalanges digging into the fabric of his shorts as he clutches at his femurs. His gaze doesn’t move from Sans’ own, and Sans can hardly keep the eye contact.

Sans is… a little dumbfounded.

“you’ve been talking shit for three years without knowing if i could see you?” Sans asks incredulously. The fact that Sans is talking to his long-time tormentor is unreal.

The devil runs a glowing red tongue over his sharp teeth, “I had a feelin’.”

“... why?” Sans utters, because it’s all he can think about. Why? Why had the other stuck around for so long without even knowing if Sans could hear or see him? Why torment him?

“Why not?” The devil replies with faux-innocence.

“thousands of monsters, billions of humans, and you couldn’t find someone more interesting? buddy, you got a messed up sense of humor.” _that’s kind of depressing_ , Sans thinks. Surely there was someone, _anyone_ out there who’d be more interesting to watch than him.

The devil in Sans’ chair shrugs. “You’re pretty fuckin’ stubborn. Three stars damned years.” He reminds Sans.

“you didn’t even know.” Sans shoots back. He falls onto his back on the bed, still taking in that for three years this devil has been following him, not knowing that Sans was aware. “... you didn’t even know.” He says again.

“Yeah.” The devil’s voice sounds kind of rough. “Three years you kept me wrapped around your little finger. You’re kinda crazy, aren’t you?”

“you just confirmed you’re not a figment of my imagination, so can’t really call me the crazy one here.”

His devil snorts. “You thought I was a hallucination?”

Slightly defensive, Sans curls in on himself and sends a weak glare over at the devil. “and what else were you supposed to be?”

The devil stands. Sans eyes him warily, then scoots back when he starts to get closer, until he’s standing right next to where Sans’ mattress is on the floor. Dozens of times his devil’s been closer, but it’s different now. When he knows that Sans knows he’s there.

Sans backs up into the corner, where his mattress meets the wall.

His devil leans even closer and unzips his jacket. Sans hadn’t even realized that it’s always been zipped up to the top. Underneath is a red sweater. Sans catches the glint of something metallic and sees that there’s an honest to delta collar on his devil’s neck.

But that isn’t what the other had wanted him to see. Below the collar is the expanse of the devil’s torso. At first, Sans doesn’t notice it.

He nearly chokes when he does.

A line of darker red, glistening in the low lighting of Sans’ shitty floor lamp. It’s blood. The shape of the cut is too familiar, Sans recognizes it from hundreds of genocide routes.

His eye lights hesitantly travel up to the devil’s face, which is calmer than it should be. His eye sockets are lidded, sharp teeth slightly parted.

“w...what?” Sans hates how his voice shakes. “are you the ghost of christmas past or something?”

His devil snorts. “Or something.” The jacket is zipped back up, and he leans back, taking a few steps away. Sans feels like a shadow’s been lifted, like he can breathe again. He doesn’t leave the corner, though.

“so.”

Crimson eye lights dilate and a sharp grin widens. “So?”

“you going to keep following me around?” Sans asks.

The devil looks Sans over. “Didn’t bother you before.”

“i didn’t think you were…” He trails off quietly and gives his devil a once over of his own. “what should i call you?”

Sans’ devil makes a curious noise. “Hm? Guess you could just call me Red.” He points to his sockets, where his red magic is obvious.

The name is fitting for him, who has red eyes, red magic, and a big red wound, but still... it’s Sans turn to snort, “knew it.” He says.

Red’s shoulders hitch as he pins Sans with an accusatory stare. “What?”

“you _are_ a lazy bastard, _red._ ”

“Oh, fuck off.” Red laughs. It’s another new laugh. Softer, fonder. Sans pretends not to notice how Red’s eye lights fuzz around the edges. He doesn’t want to deal with the sudden rush of new emotions for his devil. Red. Red devil. Heh.

Sans closes his sockets. He should sleep. But the fact that Red is right there…

“why’d the devil follow the skeleton around for three years?” Sans sets it up like he’s telling a joke. He’s not.

“Hmph, why?” Red replies.

“i dunno. you tell me.”

“....” For a few minutes, Sans thinks he won’t get an answer. _that’s fair,_ he tells himself. He’s surprised when Red speaks up, “Ever heard of something called mercy?”

“maybe a few times.”

Sans thinks about all the times the kid picked up that stick. He thinks about his brother’s spaghetti and a bright afternoon in the judgement hall, facing off a kid who had somehow done everything and nothing wrong at all. He thinks of letting them pass by him.

“Yeah.” 

Red doesn’t speak again for the rest of the night and Sans doesn’t mind. He’s still there in the morning, with another snarky comment. Sans finds his laces tied too tightly when he goes to put his shoes on.

**Author's Note:**

> i have an idea in my mind for afterfell sans, and so this fic was born... it's a one shot, but if anyone wants, i have a short idea about how red first saw sans in my head!
> 
> more on the idea of MERCY and what it means to our boyos UwU
> 
> anyways!!! [heres my tumblr (i take asks on any of the boys from my fics ;-;)](https://beanniebenn.tumblr.com/)
> 
> stay safe out there!! leave a comment if you'd like or you wanna chat!!
> 
> (fun note: the word 'devil' is used exactly 69 times within this fic, including the title/summary/notes)


End file.
